1. Field of the Invention
The invention relates to processing pixel output signals and, more particularly, to processing digital pixel output signals.
2. Background Information
With advances in digital technology, digital cameras, that is, cameras that represent the intensity of light for a given pixel location of an image in a binary digital signal format, such as with bits, are becoming more prevalent. One disadvantage of the use of such cameras, however, is the noise or offset that is sometimes encountered with the use of digital imaging arrays, such as arrays that employ charged couple device sensors or complementary-metal-oxide semiconductor sensors, hereinafter referred to as CCD sensors and CMOS sensors, respectively.
In order to address this so-called fixed pattern noise (FPN), one technique that has been employed is to read a “dark image” into memory, such as by preventing the sensors of the array from being exposed to light at a set of substantially predetermined parameters including, for example, exposure, temperature and gain factor, and storing the resulting digital pixel output signals. Then, that stored dark image is subtracted from the image of interest produced using the digital imaging array. Typically, in either hardware or software, the digital camera would ensure that corresponding pixel output signals for the desired image and the dark image are associated so that they may be appropriately subtracted or compared. However, the presence of this noise and the approach employed to address it introduces additional complexities into the processing of an image that are not present for cameras that store a signal value for the intensity of a pixel in a format other than a binary digital signal format. A need therefore exists for techniques to address the complexities that digital cameras employing these sensors present.